Small watercraft with fin and jig

ABSTRACT

This invention is an improvement to a prior invention—Small Watercraft with Fin and Sail. The improvement consists of the introductions of a rotatable water-foil means, a fin lock/release mechanism, fin rotation stoppers, rear vertical fins, end floats, and a jig/mast. The rotatable water-foil means covers a portion of the elongated member and is rotatable about the centerline of the covered portion of the elongated member. The fin lock/release mechanism installed on the elongated member consists of a wire travelling and movable along the elongated member. A vertical pin-like means is secured at a lower end of the wire. The vertical pin-like means can only move toward or away from a lower end of the elongated member. The fin rotation stoppers consist of two members. Each of the members has one end connected to the elongated member and the other end connected to the leading edge of the fin. One or more vertical fixed fins are added to the rear portion of the watercraft. One suspended float is added at each end of the watercraft and between two existing floats to produce additional buoyancy and moment when pitch polling happens. The jig/mast consists of an upper rod, a lower rod, a membrane between the rods, a mast, and a string. The leading ends of the rods are connected. The middle portions of both of the rods are secured to the mast. The upper rod is secured at the upper portion of the mast while the lower rod can be moved up and down along the mast. A string is secured to a middle portion of the trailing edge of the membrane.

FIELD OF THE INVENTION

[0001] The present invention is related to a fin and/or jig propelled small watercraft. For convenience, the illustration of this invention uses a small catamaran as the model, but the invention is also applicable to a mono hull.

BACKGROUND OF THE INVENTION

[0002] This invention is an improvement of our prior invention, A Small Watercraft with Fin and Sail, U.S. Pat. No. 6,079,344. The prior invention has a vertical shaft located in the front portion of the watercraft. Multiple foot-operated arms are secured to the upper portion of the shaft. A fin is vertically secured to a hinge which is located at the trailing end of an elongated member. The leading end of the elongated member is removably secured to a joint device at the lower end of the shaft. The arms, shaft, elongated member, and fin can rotate 360 degrees about the shaft axis. An opening between the shaft and the operator is provided to allow the elongated member together with the fin to be secured and removed during operation. A post is secured to the upper end of the shaft. The post allows a sail mast to telescope on, and the turning of the post does not affect the turning of mast or vice versa. The prior invention has a hand-controlled rudder at the rear end of the watercraft. The prior invention has basically achieved its objectives. However, it is found that the elongated member of the prior invention induces a significant amount of drag in water and affects the speed of the watercraft. Another problem is that, during sailing in a strong wind, its rotatable fin is not sufficient for controlling the watercraft moving direction, and one has to use hand to control its rear rudder for steering. Another problem is that the watercraft tends to pitch polling when the load is much off from the center longitudinally. A further problem is related to the conventional sails or jigs used on the watercraft. When a conventional sail is used, because no high tension ropes are used to flatten the sail membrane, the sail membrane tends to warp under the strong wind and makes the watercraft difficult to sail into the wind. The jig used on a small sailboat, like Sunfish, has a nearly vertical upper rod and a nearly horizontal lower rod. Because the leading end of the jig is low, part of the view will be blocked if one's head is above the lower rod. It is also noticed that because the mast is located close to the front of the jig, one have to use much force to control the jig. Furthermore, with an equivalent wind loading area, the conventional jig has a higher center of force than a jig of an equilateral triangle shape with a vertical base. Another problem is that the vertical walls of the floats are not effective enough to resist the side drift during sailing. This invention has solved all the problems. In this invention, new fin rotation stoppers which do not catch seaweed when the fin is used as the front rudder are introduced.

OBJECTIVES OF THE INVENTION

[0003] An objective of this invention is to reduce the drag caused by the elongated member of the prior invention.

[0004] Another objective of this invention is to have new fin rotation stoppers which do not catch seaweed when the fin is used as a front rudder.

[0005] Another objective of this invention is to simplify the watercraft by removing the hand-controlled rear rudder.

[0006] Another objective of this invention is to allow the operator to lock up the fin from rotation such that the fin can be used as a foot-controlled front rudder during sailing.

[0007] Another objective of this invention is to reduce the lateral drift of the watercraft during sailing.

[0008] Another objective of this invention is to reduce the pitch polling possibility of the watercraft.

[0009] A further objective of this invention is to have a jig/mast with lower center of force, provide a better view to the operator, allow lowering or raising the lower rod along the mast during sailing, and make the watercraft easier to sail into wind. The raising of the lower rod also allows the user to align both of the rods and the mast such that the jig membrane can easily wrap the rods and mast together when the jig is not in use. A string permanently attached to the membrane can conveniently be used for tying the wrapped jig and mast.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is the top view of the watercraft.

[0011]FIG. 2 is the A-A cross-section view of the watercraft shown in FIG. 1

[0012]FIG. 3 shows the B-B cross-section view of the water-foil means and the elongated member shown in FIG. 2.

[0013]FIG. 4 is the side view of the fin lock/release mechanism on the elongated member.

[0014]FIG. 5 is the top view of the leading edge of the fin.

[0015]FIG. 6 is the front view of the jig and mast.

[0016]FIG. 7 is the C-C cross-section view of the jig/mast shown in FIG. 6.

[0017]FIG. 8 is the front view of the fin rotation stoppers.

[0018]FIG. 9 is the top view of the fin rotation stoppers.

DETAILED DESCRIPTION OF THE INVENTION

[0019]FIG. 1 shows the top view of an improved watercraft. The watercraft has two floats [1]. A position adjustable seat [2] is installed close to the center of buoyancy of the two floats [1]. Multiple foot-controlled horizontal arms [3] with pedals [31] are installed in the front portion of the watercraft. A float block [41] is installed in the front portion of the watercraft between the two floats [1]. Another float block [42] is installed in the rear portion of the watercraft. Both of the blocks [41,42] are above the water line during the normal operation to reduce drag. When the watercraft is pitch polling, one of the blocks [41,42] will dip into the water and provide additional buoyancy and moment to counter further pitch polling. Thus the use of the float blocks [41,42] provides more stability to the watercraft.

[0020]FIG. 2 shows the side view of a water-foil means [11] and a portion of the watercraft. A vertical shaft [4] is installed in the front portion of the watercraft. One end of an elongated member [5] is connected to a lower end of the shaft [4] through a joint mechanism [15]. At another end of the member [5], a vertical hinge [8] is installed. A vertical fin [7] is secured to the hinge [8]. The rotation of the fin [7] about an axis of the hinge [8] is limited by stoppers [9]. Multiple horizontal arms [3] are secured to an upper end of the shaft [4]. At the free end of each arm [3], a raised pedal [31] is installed for the operator to push the arm [3] by foot. The arms [3] turn the shaft [4], and the shaft [4] sways the elongated member [5] and the fin [7]. When the arms [3] are pushed forward alternately, the fin [7] sways like a fishtail. The arms [3] together with the elongated member [5] can make a 360-degree rotation. Depending on the direction that the elongated member [5] is generally pointing to, the fin [7] can propel the watercraft forward, backward, and make turns. A removable jig/mast (not shown) can be installed right above the shaft [4]. The mast is held in place by loosely telescoping it onto a post [10] that may be formed as an extension of the upper end of the shaft [4]. When the jig/mast is on, the mast does not rotate about its axis when the shaft [4] rotates. When there is not enough wind, one can use the fin [7] to propel and steer the watercraft with or without the mast on. It is shown that when the elongated member [5] points to the rear end of the watercraft, the fin [7] is located generally right below the seat [2]. This positional arrangement of the fin [7] and the seat [2] can eliminate the wiggling of the watercraft when the fin [7] sways in water. A vertical fixed fin [12] is installed in the rear portion of each of the floats [1].

[0021]FIG. 3 shows the B-B cross-section view of the water foil means shown in FIG. 2 The water foil means [11] covering a portion of the elongated member [5] can rotate about a longitudinal centerline of the portion of the elongated member [5]. When the watercraft moves and/or the elongated member [5] sways, the airfoil means [11] can turn to the direction of water flow thus to reduce the drag caused by the elongated member [5].

[0022]FIG. 4 shows the side view of the fin lock/release mechanism on the elongated member [5] and a corresponding part on the leading edges of the fin [7]. A stud [21] is installed on an upper portion of the elongated member [5]. A control handle [22] is pivotally secured on a free end portion of the stud [21]. At one end of the handle [22], one upper end of a semi-rigid wire [23] is connected. The wire [23] travels along the elongated member [5] in a confined space. Because of the confined space, by pushing or pulling the wire [23] at the upper end, a lower end of the wire [23] will move forward or backward accordingly. At the lower end of the wire [23], a vertical pin [24] is secured. The vertical pin [24] is confined in a narrow space along the elongated member [5] that it can only move straight toward or away from the hinge [8]. The movement of the pin [24] is controlled by the handle [22] through the wire [23]. When the handle [22] rotates counter-clockwise, the pin [24] moves toward the hinge [8] or vise versa.

[0023]FIG. 5 shows the top view of leading edge of the fin [7]. A member [27] and a longer member [25] are spaced from each other and secured to the leading edges of the fin [7]. Each of the members [25,27] shown is in a plate form, however it can be in other forms. After the pin [24] moves into a space [28] between the two members [25, 27], the fin [7] is locked from rotation. After the pin [24] moves back and out of the space [28], the fin [7] is released for its limited rotation. The length difference of the two members [25,27] allows the pin [24] to stop the rotation of the fin [7] first before sliding into the space [28]. When the locked fin [7] is turned to the front of the watercraft, it becomes a foot-controlled front rudder during sailing. The rear fin [12] shown in FIG. 2 together with the locked fin [7] provide effective steering control and reduction of the lateral drift during sailing. Various ways of fin locking design can be derived by following the same idea. For an example, instead of using a pin [24] to move into the space [28] to let the fin [7] hold the pin [24] as described above, a fork can be added to each ends of a flat pin to hold a fin having a simple plate-like leading edge.

[0024]FIG. 6 shows the front view of a jig/mast configuration. The jig consists of an upper rod [52] and a lower rod [53]. A leading end of the upper rod [52] is loosely connected to a leading end of the lower rod [53] by a hinge-like means [54]. A jig membrane [55] is secured between the two rods [52,53]. A string [59] are installed in the middle of a trailing edge of the membrane [55]. The upper rod [52] is secured to an upper portion of a mast [50] by a pivot [51]. A hook-like means [57] with its opening facing to the hinge-like means [54] is secured to the lower rod [53]. When the distance between the hinge-like means [54] and the hook-like means [57] is about the same as or greater than the distance between the hinge-like means [54] and the pivot [51], a leading end of the jig where the hinge-like means [54] is located is high such that the operator's front view is not blocked by the jig. The distance from the hinge-like means [54] to the mast [50] is slightly less than the distance from the hinge-like means [54] to the center of wind force of the jig. The distance from the hinge-like means [54] to the mast [50] is also slightly less than the distance from the hinge-like means [54] to the center of gravity of the jig. When the jig is propelling the watercraft, the location of the mast [50] with respect to the center of wind force ensures that one does not need to use much force to hold the jig, and, when the jig is released in the wind, it can also easily turn and point to the wind to shed off wind pressure. The location of the mast [50] with respect to the center of gravity ensures that the rear portion of the jig is heavier and the mast [50] will stay in the hook [57] due to the weight of the jig. When the operator wants to remove the jig/mast, he can hold a lower portion of the lower rod [53] and push the connected ends of the rods [52,53] up until the rods [52,53] are aligned with the mast [50]. He then can use the membrane [55] to wrap the rods and use the string [59] to tie the wrapped jig. This arrangement also ensures a minimum storage length after the mast [50] and the rods [52,53] are tied together. A protrusion [58] installed on the mast [10] is to block the hook [57] as well as the lower rod [53] from moving up unintentionally in the wind. A backward pull of the lower rod [53] can release the block. Instead of the hook-like means [57], a ring (not shown) secured to the lower rod [53] can also be used for holding the mast [50] thus to loosely secure the lower rod [53] to the mast [50]. This jig/mast configuration is also applicable to a traditional small sailboat.

[0025]FIG. 7 is the C-C cross-section view of the jig/mast shown in FIG. 6.

[0026]FIG. 8 is the front view of two fin rotation stoppers [91]. One end of each of the stoppers [91] is secured to the elongated member [5]. Another end of each of the stoppers [91] is secured to the leading edge of the fin [7]. The configuration of the fin lock/release mechanism shown in FIG. 4 and FIG. 5 can be used along with the fin rotation stopper [91].

[0027]FIG. 9 is the top view of the fin rotation stoppers [91]. The rotation angle of the fin [7] is limited by the length of each of the stoppers [91]. In comparing with the stoppers [9] shown in FIG. 4 and FIG. 5, because the stoppers [91] connect the elongated member [5] and the fin [7], there is lesser chance for the stoppers [91] to catch seaweed when the fin [7] is used as a front rudder. The fin rotation stopping function can be achieved by various designs of the stoppers [91]. One simple design is to have the stoppers [91] made of flexible material, like strings.

[0028] Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. 

I claim:
 1. An elongated member of a small watercraft with fin and jig being covered by a water-foil means; said water-foil means being rotatable about a longitudinal centerline of a covered portion of the elongated member.
 2. A fin lock/release mechanism installed on an elongated member of a small watercraft with fin and jig consisting of a wire traveling and movable along the elongated member; a control handle being connected to an upper end of the wire; a pin-like means movable along the elongated member being vertically secured to a lower end of the wire.
 3. A jig/mast of a small watercraft consisting of an upper rod, a lower rod, a mast, and a membrane between the upper and lower rods; a leading end of the upper rod being loosely connected to a leading end of the lower rod; the upper rod being pivotally secured to an upper portion of the mast; a hook or a ring secured to the lower rod being used to loosely secured to the mast; a distance from leading ends of the upper and lower rods to the mast being slightly less than a distance from the leading ends to a center of wind force of the jig; the distance from the leading ends of the upper and lower rods to the mast being also slightly less than a distance from the leading ends to a center of gravity of the jig.
 4. A jig/mast according to claim 3 in which a distance between the leading end of the lower rod to where the lower rod is loosely secured to the mast is about the same as a distance between the leading end of the upper rod to where the upper rod is secured to the mast.
 5. A jig/mast according to claim 3 in which a string is installed in a middle portion of a trailing edge of the membrane. 